package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.collection.CollUtil;
import cn.hutool.core.util.StrUtil;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.controller.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import static com.hmdp.controller.utils.RedisConstants.BLOG_LIKED_KEY;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {

    @Resource
    private IUserService userService;
    @Resource
    private IBlogService blogService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Override
    public Result queryBlogById(Long id) {
        Blog blog = getById(id);
        if (blog == null){
            return Result.fail("笔记不存在！");
        }
        queryBlogUser(blog);
        isBlogLiked(blog);
        return Result.ok(blog);
    }

    @Override
    public Result likeBlog(Long id) {
        Long userId = UserHolder.getUser().getId();
        String key = BLOG_LIKED_KEY + id;
        Double success = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        if (success == null){
            boolean isSuccess = update().setSql("liked = liked + 1")
                    .eq("id", id)
                    .update();
            if (isSuccess){
                stringRedisTemplate.opsForZSet().add(key,userId.toString(),System.currentTimeMillis());
            }
        }else {
            boolean isSuccess = update().setSql("liked = liked - 1")
                    .eq("id",id)
                    .update();
            if (isSuccess){
                stringRedisTemplate.opsForZSet().remove(key,userId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result queryBlogLikes(Long id) {
        String key = BLOG_LIKED_KEY + id;
        Set<String> top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if (CollUtil.isEmpty(top5)){
            return Result.ok(Collections.emptyList());
        }
        List<Long> userIds = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        String userIdStr = StrUtil.join(",",userIds);

        List<UserDTO> userDTOList = userService.query()
                .in("id",userIds).last("ORDER BY FIELD(id," + userIdStr + ")").list()
                .stream()
                .map(user -> BeanUtil.copyProperties(user,UserDTO.class))
                .collect(Collectors.toList());
        return Result.ok(userDTOList);
    }


    private void queryBlogUser(Blog blog){
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }
    private void isBlogLiked(Blog blog){
        Long userId = UserHolder.getUser().getId();
        String key = BLOG_LIKED_KEY + blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key,userId.toString());
        blog.setIsLike(score != null);
    }


}
